ISP and JTAG headers

[Cirkit]

Hello,

I am fairly new to micro-controller programming. I am trying to read the code on a circuit containing an Atmel ATmega328P.

Here is a photo of the ISP header on the board:



How do I connect an Atmel programmer to the header without permanently soldering to it?

Also, how will I know if it is possible to read the code from the device or if the fuses have been set to prevent this?

Thanks.

 

[(*steve*)]

1) temporarily solder wires to it.

2) no

 

[Cirkit]

I'd rather not solder to the pads even temporarily. How would they connect to the header in a production environment?

Could you please be more specific about what you meant by no? Will I not be able to read the code from the device?

 

[Harald Kapp]

How would they connect to the header in a production environment?

Pogo pins make contact to the vias using spring pressure. You could build an adapter using pogo pins in the correct position plus some means of pressing the adapter firmly to the PCB to ensure good contact.
That's going to take a lot more effort than temporarily soldering wires to the PCB.

Could you please be more specific about what you meant by no? Will I not be able to read the code from the device?

If the fuses are set, you won't be able to read the code from the device. If the fuses are not set, you will be able to read from the device. That's what these fuses are for.

 

[Cirkit]

Pogo pins make contact to the vias using spring pressure. You could build an adapter using pogo pins in the correct position plus some means of pressing the adapter firmly to the PCB to ensure good contact.
That's going to take a lot more effort than temporarily soldering wires to the PCB.


If the fuses are set, you won't be able to read the code from the device. If the fuses are not set, you will be able to read from the device. That's what these fuses are for.

Thanks Harald, I'll try and build a jig with Pogo pins on strip board. How long will I need to hold the pins on to read/program the micro-controller?

 

[Harald Kapp]

How long will I need to hold the pins on to read/program the micro-controller?

Until teh programmer tells you it has successfully finished .
In seconds that depends on the amount of data to be transferred.

 

[(*steve*)]

Are you aware of what you'll get if you can read the code space?

I hope your next question isn't "How do I convert it back to C code?"

 

[Cirkit]

Are you aware of what you'll get if you can read the code space?

I hope your next question isn't "How do I convert it back to C code?"

Good point! I guess I was initially expecting C/program code but it'll just be machine code!

 

[(*steve*)]

for more information see this http://forum.arduino.cc/index.php?topic=3566.0